Does Getting Your Tonsils Out Make You Fat?

After children undergo a tonsillectomy, parents may want to feed them low-fat frozen yogurt instead of ice cream.

A team of researchers from St. Louis University in Missouri found that getting the tonsils removed could lead kids to pack on the pounds. The research, presented yesterday (Sept. 29) at the annual meeting of the American Academy of Otolaryngology-Head and Neck Surgery in Boston, indicates that tonsillectomy may increase a child's risk of obesity.

The researchers, who reviewed nine studies published between 1970 and 2009, found that an increase in a child's weight and body mass index (a measure of body fat) could be seen for up to seven years after the operation.

In the three studies that measured body mass index, researchers found increases of 5.5 percent to 8.2 percent after surgery.

The other six studies examined kids' pre- and post-surgery weight. Of the 668 children in those studies, the researchers found that at least 46 percent gained more weight after having their tonsils removed than would be expected for children of their age.

"I was surprised by the consistency of the results," otolaryngologist and co-presenter Anita Jeyakumar said. "Whether the children were underweight, normal weight or obese, they were likely to gain much more than expected," if they had their tonsils out.

The mechanisms behind weight gain are unclear, but Jeyakumar hypothesizes that improved health may be a factor. Many children in need of a tonsillectomy suffer from frequent illness or sleep apnea, a condition in which breathing is repeatedly interrupted during sleep . Tonsillectomy removes the cause of those health problems, and as a result may increase appetite.

This was not such a problem 20 years ago when fewer children were overweight, the researchers said. Now, however, one in every three U.S. kids is overweight or obese. The increase in the number of overweight children in her own clinic is what led Jeyakumar to investigate the relationship between weight and surgery in the first place.

"In general, surgery on overweight patients is riskier, but now that we've found a risk of additional weight gain after surgery, we really need to create standard criteria for dealing with these children," Jeyakumar said.

For example, Jeyakumar enrolls kids in weight management before they are eligible for a tonsillectomy. Doctors at other medical facilities follow similar protocol, but not all.

Still, more research is necessary before new standards can be created. It's not known whether the age at which a child has a tonsillectomy affects their risk of gaining weight. And the nine studies reviewed in this research varied in their study designs and methods, so the research is more suggestive than conclusive, Jeyakumar said.

"No one has ever examined this on a large scale, so we really need bigger studies," Jeyakumar told MyHealthNewsDaily. "In the meantime, we need to follow up with kids after surgery and really monitor them closely."